Plugboard contactors



XNVENT R A''TONEY C. D. LAKE PLUGBOARD CONTACTORS Filed DSG.

June 4, 1946.

Patented June 4, 1946 PLUGBOARD CONTACTORS Clair D. Lake, Binghamton, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application December 15, 1944, Serial No. 568,264

3 Claims. l

'I'his invention relates to contactors for use in the plugboard or circuit connecting panels of electric accounting machines. Y

The principal object of the invention is to provide an improved and simplied contactor arrangement to the end that better electrical contact will be obtained between the contacting elements.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawing, which discloses, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawing:

Fig. 1 is an enlarged view of the several separable parts oi the contactor assembly in oper-V ating relationship with one another.

Fig. 2 is an elevation of the parts in Fig. 1.

Fig. 3 is a perspective of the tip of the central element of the contactor assembly.

The particular type of plugboard for electric accounting machines to which the present invention appliesis that shown in the patent to C. D. Lake No. 2,111,118 granted March 15, 1938, in which there is provided a iixed plugboard containing rows and columns of spring contactors and an insertible plugboard in which there are corresponding rows and columns of comparison contactors xedly secured to this board, This latter board is arranged to be swung' into engagement with the first board so that electric contact is effected between oppositely located contactors on the two boards.

Referring to Figs. 1 and 2, 9 represents the fixed plugboard panel similarly identified in the patent and I represents the removable plugboard panel also so identified in the patent.

In each opening through the fixed panel 9 there is inserted a contactor II secured in position by shoulders I2 against longitudinalmovement. The contactor I Ihas a pair of oppositely facing spring blades I3 integral therewith and configured as shown. A wired plug Il is insertible in contactor II as indicated to electrically connect the same in any suitable circuit.

In the movable panel Ill there is inserted a contactor generally designated I also held in position against longitudinal movement by shoulders I6. Integral with this contactor is a pair of fiat oppositely facing spring blades I1 whose extremities are Joined at one side by a bridge I8. When the plugboard panels are moved into operative relationship as in Figs. 1 and 2, the ends of blades I1 slide between the ends of blades I3 to effect 2 electrical connection between the two, and the tension in blades I3 is such as to urge the blades I8 together.

The usual terminal plate I9 covers the ends of contactors I5 to guard against inadvertent short circuiting, and this plate is provided with holes 20 through which plugging jacks 2I may be inserted into the contactor I5.

In accordance with the present invention, the plugging jack 2| comprises a circular stem 22 with a. conical tip 23 and a conical shoulder 24. With the panel I0 moved away from fixed panel 9, jack 2| may be inserted into contactor I5 and, as it is inserted, the tip 23 will engage and part blades I1 as the tip moves past the narrow section of the curved blades. Thereafter, the blades spring back behind the tip 23 and by bearing f against sloped shoulder 24 urge the jack inwardly and hold it in position.

When jacks 2I have been inserted in the several positions on board I0, the entire board is brought into engagement with the fixed board as explained in the patent referred to, and the free ends of each pair of blades I1 will slide between the companion blades I3, which latter will then exert additional pressure to squeeze blades Il more rmly against jack stem 22 to in effect lock the stem in position.

There is thus provided a jack and plug arrangement whereby a plug jack is initially inserted against the relatively light spring tension of blades I1 and detented in position through the configuration of the plug and blades. When the plugboard panels are-brought into cooperative relationship, the additional tension of spring blades I3 is added to that of blades I1 to more securely grip and hold the jack against removal while the panels are in the relative positions of Figs. 1 and 2.

The bridge I8 serves to maintain the extremities of blades I1 at a predetermined spacing and prevent their inadvertent spreading., 'I'he parts are so proportioned that in operative position as shown in Fig. 1 blades I'I acting against shoulder 2l constantly urge the stem 22 toward the left and press shoulder 25 of the jack firmly against panel I9, vso that good electrical contact is made between blades I1 and shoulder 24.

While there have been shown and described and pointed out the fundamental novel features of the invention as appliedv to a single modiiication, vit will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without deporting from the spirit o! the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

` What is claimed is:

1. In s machine h avins a ilxed plugboerd panel and a removable panel. the combination of. spring contnctor secured in the :fixed paneLLa second spring contactor secured in the removable panel. and s plug jack insertible in the second spring conictorl said second contactar being configured to resiliently grip and hold the inserted jack and scid iirst named contacter being configured to engage the second contacter to increase the tencion thereof, whereby to grip the jack more securely.

4 2. Theinvention set forth in claim 1 in which the-second contacter is bifurcated to form n ps'ir of spring blades between which the Jack is in- V alerted and the iirst contactor is also bifurcated to form a pair of spring `bliides between which the blades of the second contactar enter.

3. 'I'he invention set forth in claim 1, in which the second contactor is bifurcated to form n Pair of oppositely curved spring blades between which the jack is inserted and the Jack is provided with a. shoulder for engagement with the curved blades.

Y -CLAIRD.LAKE. 

